gather_data() {
    if (check_function()) {

    }

    print letter
}

print_letter() {
    if (check_function()) {

    }
}

int check_function(int v0) {
    static int result = 0;
    static int args = 0; //v0 cannot be == 0

    if (args == v0)
        return result;

    otherwise CALCULATIONS (database call)!
    args = v0;
    result = result;
}